Pub Date : 2025-12-24DOI: 10.1109/TMAG.2025.3647779
Amrutha R Menon;Hemprasad Yashwant Patil;Ashutosh Mahajan;Niroj Kumar Sahu
This work presents, for the first time, a physics-informed neural network (PINN) model for magnetic hyperthermia, a promising non-invasive cancer therapy known for its high efficacy and minimal side effects. Effective cancer cell destruction requires heating to 42 °C-45 °C. The heat generated by magnetic nanoparticles (MNPs) under an alternating magnetic field depends strongly on their physicochemical properties. Hence, the optimization of MNP for effective heat generation remains a key challenge and constitutes the fundamental motivation of this study. In this work, we study and compare various approaches using regression models, artificial neural network (ANN), and PINN to address the challenges associated with magnetic fluid hyperthermia (MFH) prediction and analysis. The model incorporates input parameters, including particle size, saturation magnetization, magnetic field intensity, frequency, specific heat of fluid, nanoparticle (NP) concentration, and time, to predict temperature evolution as the output. The dataset is compiled from our published research work, comprising 3690 data points, ensuring sufficient variability and robustness for model training and evaluation. Our PINN model shows an excellent R2 value of around 0.98 against the test data.
{"title":"Physics-Informed and Data-Driven Machine Learning for Magnetic Hyperthermia of Fe3O4 Nanoparticles","authors":"Amrutha R Menon;Hemprasad Yashwant Patil;Ashutosh Mahajan;Niroj Kumar Sahu","doi":"10.1109/TMAG.2025.3647779","DOIUrl":"https://doi.org/10.1109/TMAG.2025.3647779","url":null,"abstract":"This work presents, for the first time, a physics-informed neural network (PINN) model for magnetic hyperthermia, a promising non-invasive cancer therapy known for its high efficacy and minimal side effects. Effective cancer cell destruction requires heating to 42 °C-45 °C. The heat generated by magnetic nanoparticles (MNPs) under an alternating magnetic field depends strongly on their physicochemical properties. Hence, the optimization of MNP for effective heat generation remains a key challenge and constitutes the fundamental motivation of this study. In this work, we study and compare various approaches using regression models, artificial neural network (ANN), and PINN to address the challenges associated with magnetic fluid hyperthermia (MFH) prediction and analysis. The model incorporates input parameters, including particle size, saturation magnetization, magnetic field intensity, frequency, specific heat of fluid, nanoparticle (NP) concentration, and time, to predict temperature evolution as the output. The dataset is compiled from our published research work, comprising 3690 data points, ensuring sufficient variability and robustness for model training and evaluation. Our PINN model shows an excellent R2 value of around 0.98 against the test data.","PeriodicalId":13405,"journal":{"name":"IEEE Transactions on Magnetics","volume":"62 2","pages":"1-10"},"PeriodicalIF":1.9,"publicationDate":"2025-12-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146082290","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-23DOI: 10.1109/TMAG.2025.3647738
Limei Yan;Yingjie Li;Yuanyuan Li;Jing Liu;Guoqiang Liu
The state of blood flow in blood vessels has an inseparable relationship with cardiovascular diseases (CVDs). To facilitate convenient blood flow monitoring, this study investigates the relationship between blood flow and the electric field in an electromagnetic blood flowmeter using a permanent magnet as the excitation source through modeling and simulation. First, for the case of a uniform magnetic field and noninvasive measurement, a mathematical model of the target blood region was established, providing a numerical relationship between blood flow and the potential distribution generated under a uniform magnetic field. Subsequently, the effects and offsets caused by a nonuniform magnetic field generated by a permanent magnet were analyzed, and the corresponding models were simulated using COMSOL. By combining the simulation results with numerical solutions, a quantitative expression was constructed to describe the relationship between the voltage measured across symmetric electrodes and blood flow under a nonuniform magnetic field. Finally, experimental measurements were conducted under practical conditions, yielding a measured voltage within 5 μV of simulated predictions, thereby providing a valuable reference for the further development and portable application of electromagnetic blood flowmeters.
{"title":"Noninvasive Blood Flow Measurement Using Electromagnetic Method Under Nonuniform Magnetic Fields","authors":"Limei Yan;Yingjie Li;Yuanyuan Li;Jing Liu;Guoqiang Liu","doi":"10.1109/TMAG.2025.3647738","DOIUrl":"https://doi.org/10.1109/TMAG.2025.3647738","url":null,"abstract":"The state of blood flow in blood vessels has an inseparable relationship with cardiovascular diseases (CVDs). To facilitate convenient blood flow monitoring, this study investigates the relationship between blood flow and the electric field in an electromagnetic blood flowmeter using a permanent magnet as the excitation source through modeling and simulation. First, for the case of a uniform magnetic field and noninvasive measurement, a mathematical model of the target blood region was established, providing a numerical relationship between blood flow and the potential distribution generated under a uniform magnetic field. Subsequently, the effects and offsets caused by a nonuniform magnetic field generated by a permanent magnet were analyzed, and the corresponding models were simulated using COMSOL. By combining the simulation results with numerical solutions, a quantitative expression was constructed to describe the relationship between the voltage measured across symmetric electrodes and blood flow under a nonuniform magnetic field. Finally, experimental measurements were conducted under practical conditions, yielding a measured voltage within 5 μV of simulated predictions, thereby providing a valuable reference for the further development and portable application of electromagnetic blood flowmeters.","PeriodicalId":13405,"journal":{"name":"IEEE Transactions on Magnetics","volume":"62 2","pages":"1-11"},"PeriodicalIF":1.9,"publicationDate":"2025-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146082303","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-22DOI: 10.1109/TMAG.2025.3646805
Jianwei Wang;Zheng Zhang;Jiaxing Peng;Zheng Cheng;Panpan Zuo;Qinwei Li;Tieqiao Hu
In this article, a low-cost magnetic-field probe ($H$ -field probe) with enhanced gain flatness is designed, fabricated, and calibrated. The symmetrical probe body structure, combined with a side-plug sub miniature version A (SMA) connector, enables the proposed $H$ -field probe to measure the tangential magnetic fields ($H_{x}$ and $H_{y}$ ) in one-time measurement via coaxial rotation, resulting in an enhanced measurement efficiency of about 30% without reloading the probe repeatedly during the measurement. The designed loop aperture and symmetric chamfered edge (SCE) effectively suppress resonances and ripples, achieving an average fluctuation of about 1.25 dB and a maximum fluctuation of less than 2 dB in terms of the proposed $H$ -field probe's $left|S_{21}right|$ . The proposed $H$ -field probe maintains a high common-mode suppression of more than 30 dB within 9 kHz-20 GHz and a 13.23 dB suppression to the differential-mode coupling at 5 GHz with an extremely low cost.
{"title":"A Low-Cost H-Field Probe With Coaxial Rotation for Magnetic-Field Scanning","authors":"Jianwei Wang;Zheng Zhang;Jiaxing Peng;Zheng Cheng;Panpan Zuo;Qinwei Li;Tieqiao Hu","doi":"10.1109/TMAG.2025.3646805","DOIUrl":"https://doi.org/10.1109/TMAG.2025.3646805","url":null,"abstract":"In this article, a low-cost magnetic-field probe (<inline-formula> <tex-math>$H$ </tex-math></inline-formula>-field probe) with enhanced gain flatness is designed, fabricated, and calibrated. The symmetrical probe body structure, combined with a side-plug sub miniature version A (SMA) connector, enables the proposed <inline-formula> <tex-math>$H$ </tex-math></inline-formula>-field probe to measure the tangential magnetic fields (<inline-formula> <tex-math>$H_{x}$ </tex-math></inline-formula> and <inline-formula> <tex-math>$H_{y}$ </tex-math></inline-formula>) in one-time measurement via coaxial rotation, resulting in an enhanced measurement efficiency of about 30% without reloading the probe repeatedly during the measurement. The designed loop aperture and symmetric chamfered edge (SCE) effectively suppress resonances and ripples, achieving an average fluctuation of about 1.25 dB and a maximum fluctuation of less than 2 dB in terms of the proposed <inline-formula> <tex-math>$H$ </tex-math></inline-formula>-field probe's <inline-formula> <tex-math>$left|S_{21}right|$ </tex-math></inline-formula>. The proposed <inline-formula> <tex-math>$H$ </tex-math></inline-formula>-field probe maintains a high common-mode suppression of more than 30 dB within 9 kHz-20 GHz and a 13.23 dB suppression to the differential-mode coupling at 5 GHz with an extremely low cost.","PeriodicalId":13405,"journal":{"name":"IEEE Transactions on Magnetics","volume":"62 2","pages":"1-7"},"PeriodicalIF":1.9,"publicationDate":"2025-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146082302","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Using the seed-mediated high-temperature decomposition method, we synthesized $mathrm{CoFe}_2 mathrm{O}_4 text {@} mathrm{NiFe}_2 mathrm{O}_4$ core/shell nanoparticles with controlled shell thicknesses from $sim 1$ to 6 nm and evaluated their performance in magnetic hyperthermia. A clear enhancement in heating efficiency was observed, with specific absorption rate (SAR) values increasing from $sim 40 mathrm{~W} cdot mathrm{~g}^{-1}$ for bare $mathrm{CoFe}_2 mathrm{O}_4$ to $sim 80 mathrm{~W} cdot mathrm{~g}^{-1}$ for the thickest-shell sample. This trend is attributed to optimized magnetic anisotropy and particle volume, enhancing thermal stability and energy dissipation under alternating magnetic fields (AMFs) below Hergt-Dutz limit. These findings support the strategic design of hard and soft ferrite architectures for biomedical heating applications. Although the particles are capped with oleate ligands from the synthesis, these results highlight the tunability of hard and soft ferrite systems and offer insight into the future design of biocompatible hyperthermia agents.
{"title":"Shell Thickness-Dependent Anisotropy in CoFe2O4@NiFe2O4 Core/Shell Nanoparticles for Magnetic Heating","authors":"A. Omelyanchik;S. Villa;F. Canepa;G. Singh;F. Brero;A. Lascialfari;Ž. Fabriciová;P. Hrubovčák;A. Zeleňáková;D. Peddis","doi":"10.1109/TMAG.2025.3646767","DOIUrl":"https://doi.org/10.1109/TMAG.2025.3646767","url":null,"abstract":"Using the seed-mediated high-temperature decomposition method, we synthesized <inline-formula> <tex-math>$mathrm{CoFe}_2 mathrm{O}_4 text {@} mathrm{NiFe}_2 mathrm{O}_4$ </tex-math></inline-formula> core/shell nanoparticles with controlled shell thicknesses from <inline-formula> <tex-math>$sim 1$ </tex-math></inline-formula> to 6 nm and evaluated their performance in magnetic hyperthermia. A clear enhancement in heating efficiency was observed, with specific absorption rate (SAR) values increasing from <inline-formula> <tex-math>$sim 40 mathrm{~W} cdot mathrm{~g}^{-1}$ </tex-math></inline-formula> for bare <inline-formula> <tex-math>$mathrm{CoFe}_2 mathrm{O}_4$ </tex-math></inline-formula> to <inline-formula> <tex-math>$sim 80 mathrm{~W} cdot mathrm{~g}^{-1}$ </tex-math></inline-formula> for the thickest-shell sample. This trend is attributed to optimized magnetic anisotropy and particle volume, enhancing thermal stability and energy dissipation under alternating magnetic fields (AMFs) below Hergt-Dutz limit. These findings support the strategic design of hard and soft ferrite architectures for biomedical heating applications. Although the particles are capped with oleate ligands from the synthesis, these results highlight the tunability of hard and soft ferrite systems and offer insight into the future design of biocompatible hyperthermia agents.","PeriodicalId":13405,"journal":{"name":"IEEE Transactions on Magnetics","volume":"62 2","pages":"1-6"},"PeriodicalIF":1.9,"publicationDate":"2025-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146082304","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The ferrite phase shifter (FPS) is a microwave device that utilizes the gyromagnetic properties of ferrite materials to achieve phase shift. It offers advantages such as fast switching speed, low insertion loss (IL), and high reliability, making it widely used in phased array antenna (PAA) systems. However, the power handling capability (PHC) of Ku-band FPSs remains inadequate, limiting their application in high-power microwave (HPM) phased array systems. Based on the theory of ferrite gyromagnetism and the structure of the latching non-reciprocal FPS, this article derives a transcendental equation for the phase constant of the device. Expressions for the internal field distribution and power distribution are obtained. The interrelationships among phase-shifting efficiency, PHC, and various structural parameters are analyzed, leading to recommended value ranges for the structural parameters of high-power FPSs, thereby providing a theoretical foundation for phase shifter (PS) design. The ferrite material is another critical factor influencing the PHC. The high-power quality factor of the ferrite material is introduced, serving as a criterion for material selection. On this basis, the design, optimization, and development of a latching non-reciprocal double-toroid FPS have been completed. Through appropriate selection of structural parameters, improvement of ferrite material properties, and enhanced integration techniques, the PHC of the Ku-band FPS has been increased to over 500 kW, with an IL of less than 1.3 dB and a maximum differential phase shift (MDPS) of approximately 400°.
{"title":"Research on the Power-Handling Capability of Latching Non-Reciprocal Ferrite Phase Shifters","authors":"Xianggang Hu;Jiancang Su;Yue Ying;Mei Li;Rui Li;Jie Cheng;Shaotong Wu;Min Guo;Haichuan Zhang;Qi Wang;Fengzi Liu","doi":"10.1109/TMAG.2025.3646997","DOIUrl":"https://doi.org/10.1109/TMAG.2025.3646997","url":null,"abstract":"The ferrite phase shifter (FPS) is a microwave device that utilizes the gyromagnetic properties of ferrite materials to achieve phase shift. It offers advantages such as fast switching speed, low insertion loss (IL), and high reliability, making it widely used in phased array antenna (PAA) systems. However, the power handling capability (PHC) of Ku-band FPSs remains inadequate, limiting their application in high-power microwave (HPM) phased array systems. Based on the theory of ferrite gyromagnetism and the structure of the latching non-reciprocal FPS, this article derives a transcendental equation for the phase constant of the device. Expressions for the internal field distribution and power distribution are obtained. The interrelationships among phase-shifting efficiency, PHC, and various structural parameters are analyzed, leading to recommended value ranges for the structural parameters of high-power FPSs, thereby providing a theoretical foundation for phase shifter (PS) design. The ferrite material is another critical factor influencing the PHC. The high-power quality factor of the ferrite material is introduced, serving as a criterion for material selection. On this basis, the design, optimization, and development of a latching non-reciprocal double-toroid FPS have been completed. Through appropriate selection of structural parameters, improvement of ferrite material properties, and enhanced integration techniques, the PHC of the Ku-band FPS has been increased to over 500 kW, with an IL of less than 1.3 dB and a maximum differential phase shift (MDPS) of approximately 400°.","PeriodicalId":13405,"journal":{"name":"IEEE Transactions on Magnetics","volume":"62 2","pages":"1-12"},"PeriodicalIF":1.9,"publicationDate":"2025-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146082315","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-19DOI: 10.1109/TMAG.2025.3646166
Peng-Cheng Yang;Ji-Zhong Zhao;Meng-Xue Liu;Yu-Lin Guo;Qi Yang;Qian Zhao;Suo Bai;Yan-Li Liu;Zhu-Bai Li
RE2(Fe,Co)14B magnets bear a high Curie temperature, but their coercivity decreases due to the poor crystal structure stability of RE2(Fe,Co)14B. In this article, Al element was added into RE–(Fe,Co)–Al–B magnets, and the coercivity increases monotonously with the addition of Al elements. For Al content of 0.8 at.%, the coercivity increases to 18.6 kOe in RE14(Fe,Co)79.5Al0.8B5.7 magnets, and the remanence does not decrease obviously. Whereas the content of Al is more than 1.2 at.%, the degree of increase in coercivity reduces, and the remanence decreases obviously. There exists the minor phase of RE(Fe,Co)2 phase, RE-rich phase, and RE–oxide in the sintered RE–(Fe,Co)–Al–B magnets. For the high content of Al, the amount of RE(Fe,Co)2 phase increases, and so the remanence obviously decreases. The addition of the Al element leads to an increase in the melt-point of RE2(Fe,Co)14B phase, and the range of phase transition temperature is narrowed, implying the improvement in the structure stability of RE2(Fe,Co)14B crystals. The magnetocrystalline anisotropy decreases a little due to the addition of the Al element, while the coercivity increases, which should be attributed to both the effects of the RE-rich phase and the improvement of crystal structure stability. The thermal stability of remanence in RE–(Fe,Co)–Al–B is much better than that in commercial Nd–Fe–B magnets, and if further improving the coercivity using the grain boundary diffusion, both the remanence and coercivity with high thermal stability are expected to be acquired in RE–(Fe,Co)–Al–B magnets.
RE2(Fe,Co)14B磁体具有较高的居里温度，但由于RE2(Fe,Co)14B晶体结构稳定性差，其矫顽力降低。本文将Al元素添加到RE - (Fe,Co) - Al - b磁体中，其矫顽力随Al元素的加入而单调增加。对于Al含量为0.8 at的。%, RE14(Fe,Co)79.5Al0.8B5.7磁体矫顽力提高到18.6 kOe，剩余物没有明显降低。而Al的含量大于1.2 at。%时矫顽力增加程度减小，剩余物明显减少。烧结后的RE- (Fe,Co) - al - b磁体中存在少量的RE(Fe,Co)2相、富RE相和RE氧化物相。随着Al含量的增加，RE(Fe,Co)2相的数量增加，剩余物明显减少。Al元素的加入提高了RE2(Fe,Co)14B相的熔点，缩小了相变温度范围，提高了RE2(Fe,Co)14B晶体的结构稳定性。Al元素的加入使磁晶各向异性略有降低，而矫顽力则有所提高，这应归因于富re相的作用和晶体结构稳定性的提高。RE - (Fe,Co) - al - b磁体剩余物的热稳定性远好于工业级Nd-Fe-B磁体，如果利用晶界扩散进一步提高矫顽力，有望获得具有高热稳定性的剩余物和矫顽力。
{"title":"Phase Analysis and Magnetic Properties in Sintered RE–(Fe,Co)–Al–B Magnets","authors":"Peng-Cheng Yang;Ji-Zhong Zhao;Meng-Xue Liu;Yu-Lin Guo;Qi Yang;Qian Zhao;Suo Bai;Yan-Li Liu;Zhu-Bai Li","doi":"10.1109/TMAG.2025.3646166","DOIUrl":"https://doi.org/10.1109/TMAG.2025.3646166","url":null,"abstract":"RE2(Fe,Co)14B magnets bear a high Curie temperature, but their coercivity decreases due to the poor crystal structure stability of RE2(Fe,Co)14B. In this article, Al element was added into RE–(Fe,Co)–Al–B magnets, and the coercivity increases monotonously with the addition of Al elements. For Al content of 0.8 at.%, the coercivity increases to 18.6 kOe in RE14(Fe,Co)79.5Al0.8B5.7 magnets, and the remanence does not decrease obviously. Whereas the content of Al is more than 1.2 at.%, the degree of increase in coercivity reduces, and the remanence decreases obviously. There exists the minor phase of RE(Fe,Co)2 phase, RE-rich phase, and RE–oxide in the sintered RE–(Fe,Co)–Al–B magnets. For the high content of Al, the amount of RE(Fe,Co)2 phase increases, and so the remanence obviously decreases. The addition of the Al element leads to an increase in the melt-point of RE2(Fe,Co)14B phase, and the range of phase transition temperature is narrowed, implying the improvement in the structure stability of RE2(Fe,Co)14B crystals. The magnetocrystalline anisotropy decreases a little due to the addition of the Al element, while the coercivity increases, which should be attributed to both the effects of the RE-rich phase and the improvement of crystal structure stability. The thermal stability of remanence in RE–(Fe,Co)–Al–B is much better than that in commercial Nd–Fe–B magnets, and if further improving the coercivity using the grain boundary diffusion, both the remanence and coercivity with high thermal stability are expected to be acquired in RE–(Fe,Co)–Al–B magnets.","PeriodicalId":13405,"journal":{"name":"IEEE Transactions on Magnetics","volume":"62 2","pages":"1-7"},"PeriodicalIF":1.9,"publicationDate":"2025-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146082294","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-19DOI: 10.1109/TMAG.2025.3646293
Yu Tang;Barry Gallacher;Zimeng Yu;Sarah Olsen
Galfenol thin films demonstrate significant potential for microelectromechanical system (MEMS) applications due to their notable magnetostrictive properties and favorable mechanical characteristics. In this study, we report an investigation into the modifications in both the amorphous and crystalline structures of galfenol thin films subjected to various direct current (dc) magnetron sputtering parameters, employing atomic force microscopy (AFM), magnetic force microscopy (MFM), and X-ray diffraction (XRD) techniques. Our results indicate that coercivity force increases with higher sputtering power but decreases as the Ar working pressure rises. Furthermore, the effects of film thickness, root mean square (rms) surface roughness, and sputtering parameters on magnetostriction were systematically investigated.
{"title":"Effects of DC Magnetron Sputtering Parameters on the Topography and Magnetic Properties of Galfenol/SiC Films","authors":"Yu Tang;Barry Gallacher;Zimeng Yu;Sarah Olsen","doi":"10.1109/TMAG.2025.3646293","DOIUrl":"https://doi.org/10.1109/TMAG.2025.3646293","url":null,"abstract":"Galfenol thin films demonstrate significant potential for microelectromechanical system (MEMS) applications due to their notable magnetostrictive properties and favorable mechanical characteristics. In this study, we report an investigation into the modifications in both the amorphous and crystalline structures of galfenol thin films subjected to various direct current (dc) magnetron sputtering parameters, employing atomic force microscopy (AFM), magnetic force microscopy (MFM), and X-ray diffraction (XRD) techniques. Our results indicate that coercivity force increases with higher sputtering power but decreases as the Ar working pressure rises. Furthermore, the effects of film thickness, root mean square (rms) surface roughness, and sputtering parameters on magnetostriction were systematically investigated.","PeriodicalId":13405,"journal":{"name":"IEEE Transactions on Magnetics","volume":"62 2","pages":"1-6"},"PeriodicalIF":1.9,"publicationDate":"2025-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146082314","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-18DOI: 10.1109/TMAG.2025.3645930
Jelena M. Orelj;Radoslav S. Surla;Vladimir. B. Pavlović;Nebojša S. Mitrović
The magnetoimpedance (MI) element of $mathrm{Co}_{72.5} mathrm{Si}_{12.5} mathrm{~B}_{15}$ amorphous wires, designed for magnetic sensors, was examined in an external axial dc magnetic field (up to $H_{text {max }} approx 15 mathrm{kA} / mathrm{m}$ ) and a frequency range of $1 mathrm{MHz} leq f leq 12 mathrm{MHz}$ . The peak value of the impedance modulus, $Z_{text {max }}$ , of approximately $100 Omega$ , was registered at a frequency of 12 MHz and an external magnetic field of $2.18 mathrm{kA} / mathrm{m}$ . A maximum MI-ratio of 384% was recorded at 1 MHz and a magnetically saturated state. The magnetic anisotropy field $H_k$ exhibits a linear increase in the operating frequency range from 1 to 7 MHz, followed by a further non-linear huge increase. The frequency dependence of the MI-ratio with the magnetic field as a parameter approved a low dc magnetic field sensing.
研究了用于磁传感器的$mathrm{Co}_{72.5} mathrm{Si}_{12.5} mathrm{~B}_{15}$非晶导线的磁阻抗（MI）元件在外部轴向直流磁场（最大$H_{text {max }} approx 15 mathrm{kA} / mathrm{m}$）和频率范围$1 mathrm{MHz} leq f leq 12 mathrm{MHz}$下的性能。阻抗模量的峰值$Z_{text {max }}$约为$100 Omega$，在12 MHz的频率和$2.18 mathrm{kA} / mathrm{m}$的外部磁场下被记录下来。最大MI-ratio为384% was recorded at 1 MHz and a magnetically saturated state. The magnetic anisotropy field $H_k$ exhibits a linear increase in the operating frequency range from 1 to 7 MHz, followed by a further non-linear huge increase. The frequency dependence of the MI-ratio with the magnetic field as a parameter approved a low dc magnetic field sensing.
{"title":"MI-Sensing Properties of CoSiB Amorphous Wires","authors":"Jelena M. Orelj;Radoslav S. Surla;Vladimir. B. Pavlović;Nebojša S. Mitrović","doi":"10.1109/TMAG.2025.3645930","DOIUrl":"https://doi.org/10.1109/TMAG.2025.3645930","url":null,"abstract":"The magnetoimpedance (MI) element of <inline-formula> <tex-math>$mathrm{Co}_{72.5} mathrm{Si}_{12.5} mathrm{~B}_{15}$ </tex-math></inline-formula> amorphous wires, designed for magnetic sensors, was examined in an external axial dc magnetic field (up to <inline-formula> <tex-math>$H_{text {max }} approx 15 mathrm{kA} / mathrm{m}$ </tex-math></inline-formula>) and a frequency range of <inline-formula> <tex-math>$1 mathrm{MHz} leq f leq 12 mathrm{MHz}$ </tex-math></inline-formula>. The peak value of the impedance modulus, <inline-formula> <tex-math>$Z_{text {max }}$ </tex-math></inline-formula>, of approximately <inline-formula> <tex-math>$100 Omega$ </tex-math></inline-formula>, was registered at a frequency of 12 MHz and an external magnetic field of <inline-formula> <tex-math>$2.18 mathrm{kA} / mathrm{m}$ </tex-math></inline-formula>. A maximum MI-ratio of 384% was recorded at 1 MHz and a magnetically saturated state. The magnetic anisotropy field <inline-formula> <tex-math>$H_k$ </tex-math></inline-formula> exhibits a linear increase in the operating frequency range from 1 to 7 MHz, followed by a further non-linear huge increase. The frequency dependence of the MI-ratio with the magnetic field as a parameter approved a low dc magnetic field sensing.","PeriodicalId":13405,"journal":{"name":"IEEE Transactions on Magnetics","volume":"62 2","pages":"1-4"},"PeriodicalIF":1.9,"publicationDate":"2025-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146082313","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Magnetic tunnel junctions (MTJs) are of great significance for the next generation ultrafast spintronic memories due to their non-volatility and nanosecond-level writing characteristics. Effective spin manipulation is the key to realizing high-speed field-free magnetic random access memories (MRAMs). In this article, the performance of applying the interlayer Dzyaloshinsky–Moriya interaction (DMI) to the conventional MTJ structure is investigated. By replacing the perpendicular free layer with a composite structure of out-of-plane free layer/coupling layer/in-plane free layer, the rapid switching of MTJs is achieved. We analyze the working conditions of the device through macrospin simulations and verify them by micromagnetic simulations. This structure significantly improves the speed at which the magnetic moment recovers to stability after the removal of external effects (voltage and current), reaching 56.25% of the traditional spin–orbit torque (SOT) MTJ. We believe that our work may promote the research and development of high-speed and field-free MRAMs in the future.
{"title":"Multilayer Field-Free Magnetic Tunnel Junction With Interlayer Dzyaloshinsky–Moriya Interaction","authors":"Rui Zhou;Haiyang Zhang;Jin He;Qijun Huang;Hao Wang;Sheng Chang","doi":"10.1109/TMAG.2025.3645739","DOIUrl":"https://doi.org/10.1109/TMAG.2025.3645739","url":null,"abstract":"Magnetic tunnel junctions (MTJs) are of great significance for the next generation ultrafast spintronic memories due to their non-volatility and nanosecond-level writing characteristics. Effective spin manipulation is the key to realizing high-speed field-free magnetic random access memories (MRAMs). In this article, the performance of applying the interlayer Dzyaloshinsky–Moriya interaction (DMI) to the conventional MTJ structure is investigated. By replacing the perpendicular free layer with a composite structure of out-of-plane free layer/coupling layer/in-plane free layer, the rapid switching of MTJs is achieved. We analyze the working conditions of the device through macrospin simulations and verify them by micromagnetic simulations. This structure significantly improves the speed at which the magnetic moment recovers to stability after the removal of external effects (voltage and current), reaching 56.25% of the traditional spin–orbit torque (SOT) MTJ. We believe that our work may promote the research and development of high-speed and field-free MRAMs in the future.","PeriodicalId":13405,"journal":{"name":"IEEE Transactions on Magnetics","volume":"62 2","pages":"1-6"},"PeriodicalIF":1.9,"publicationDate":"2025-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146082311","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This article presents a modified analytical method for evaluating the apparent power in homogenized models of conductor arrays, with particular focus on structures exhibiting periodic and regular hexagonal symmetry. For analyzing the external effect, the extended Ollendorff formula is implemented. For evaluating the internal effect, by solving the diffusion equation with Bessel functions, the apparent power inside the conductor is obtained using the Poynting theorem. The total power of the unit cell is subsequently completed through the application of Ampère’s circuital law. The accuracy of the modified analytical solution is validated against detailed finite element simulations across a wide frequency range. Results show that the modified method significantly improves the prediction of reactive power, especially in the high-frequency regime, while maintaining excellent accuracy in active power estimation. The effectiveness of the method is further demonstrated in large-scale, homogenized domains composed of multiple periodic and hexagonal cells. Detailed field distribution comparisons confirm the validity of the homogenization process.
{"title":"Modified Semianalytical Approach for Homogenization on Multicoils","authors":"Shuli Yin;Junkai Tian;Zhijiang Liang;Youpeng Huangfu;Xikui Ma;Hajime Igarashi","doi":"10.1109/TMAG.2025.3645791","DOIUrl":"https://doi.org/10.1109/TMAG.2025.3645791","url":null,"abstract":"This article presents a modified analytical method for evaluating the apparent power in homogenized models of conductor arrays, with particular focus on structures exhibiting periodic and regular hexagonal symmetry. For analyzing the external effect, the extended Ollendorff formula is implemented. For evaluating the internal effect, by solving the diffusion equation with Bessel functions, the apparent power inside the conductor is obtained using the Poynting theorem. The total power of the unit cell is subsequently completed through the application of Ampère’s circuital law. The accuracy of the modified analytical solution is validated against detailed finite element simulations across a wide frequency range. Results show that the modified method significantly improves the prediction of reactive power, especially in the high-frequency regime, while maintaining excellent accuracy in active power estimation. The effectiveness of the method is further demonstrated in large-scale, homogenized domains composed of multiple periodic and hexagonal cells. Detailed field distribution comparisons confirm the validity of the homogenization process.","PeriodicalId":13405,"journal":{"name":"IEEE Transactions on Magnetics","volume":"62 2","pages":"1-9"},"PeriodicalIF":1.9,"publicationDate":"2025-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146082238","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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